Electrical power receptacles may be incorporated into modular electrical systems that can be coupled together in a series or ganged arrangement to provide users with access to electrical power at different locations within a work area, such as in locations that are spaced from conventional wall, floor, or ceiling outlets. However, electrical power receptacles that are located remotely from walls, floors, or ceilings must be connected to a power source, such as a conventional wall or floor outlet, which creates a risk that different modules having their own dedicated power cords could be coupled to different power sources, and also coupled to one another. This can cause electrical problems ranging from out-of-phase electrical sources being electrically coupled together, to permitting excessive electrical loads to be powered without tripping a circuit breaker.